Eating lunch with TV on the Radio, the Brooklyn band ranked among this decade's finest practitioners of high-brow experimental rock music, is a disconcerting experience. We are sitting around a coffee table squeezing sachets of ketchup on to big plates of burgers and chips. Insipid hotel-lobby music floats down from above. Four of the band's five members are present (bassist Gerard Smith couldn't make it), mostly reclining on a set of grey plastic sofas.

Dave Sitek, multi-instrumentalist, producer extraordinaire, and the man recently described by NME as the most forward-thinking musician on the planet, is squatting uncomfortably on the floor. He's putting as much distance as possible, he explains, between himself and the source of the offending muzak. 'Maybe I should actually crawl under the table.'

The conversation turns to the revered American TV show The Wire, a perfect subject for a band that favours complexity and abrasiveness over easy answers and palatable pay-offs. All of which appears to confirm the various suspicions people might harbour about TV on the Radio. One is that they are too serious and downcast for their own good. Another is that their penchant for pushing musical envelopes makes them the preserve of chin-stroking, Wire magazine-reading types. But these assumptions seem untrue. The band, all in their thirties, spend most of their time joking around like a cluster of schoolkids. When I ask them about their lofty image, Kyp Malone, the band's soft-spoken guitarist, invites me to smell his finger. His bandmates collapse into fits of laughter.

TV on the Radio's new album, Dear Science, is terrific. It is the band's tightest, most focused effort to date. The sound is cleaner, and the melodies more immediate than on their two previous albums (their 2002 debut, OK Calculator, was self-released and very hard to obtain). The funk references that flickered in and out of earlier songs are made solid here, in the bass line that dominates the propulsive lead single 'Golden Age', and in the unexpected guitar lick that shines light through the darkness of 'Crying'. Horns from New York Afrobeat collective Antibalas add lively flourishes to 'Red Dress' and 'Dancing Choose'.

'The loose idea was that we wanted to make a dance record,' says Tunde Adebimpe, the band's towering lead vocalist who has a habit of raising his fist to the gods when he sings as if testifying to some formidable higher truth. 'At our gigs in the States we can get a lot of crossed-arm starers when we're playing. So we thought it would be nice to come up with something that made it a little more difficult for people to just stand there.'

TV on the Radio made an impact in 2004 when their album Desperate Youth, Blood Thirsty Babes won the prestigious Shortlist Music Prize, a US award focusing on emerging talent. The band, formed by Sitek and Adebimpe three years earlier, grew out of the fertile Brooklyn arts scene, a hotbed of musical innovation and home to acts such as Liars and Animal Collective. Between them the two friends had dabbled in painting, photography, filmmaking and acting (Adebimpe played the romantic lead in the 2001 indie film Jump Tomorrow) before they formed a band.

Desperate Youth raided the band's broad store of influences, twisting elements of soul, gospel and doo-wop into a daring new rock aesthetic. David Bowie declared himself a fan. 'I love the new record. I play it about three times a week,' he said. 'They have a strong link with the great body of American poetry, especially Beat poetry. The sampling, multitracking and mashing identifies them as the spawn of a techno-industrial society.'

The 2006 follow-up, Return to Cookie Mountain, a more assured affair, cranked up the intensity even further: a guest appearance from Bowie on 'Provinces' fell victim to sheets of guitar noise.

Their lyrics have tended towards the cryptic, the oblique, but Malone argues that this new album is different. 'There are no mysteries going on here, from my perspective,' he says. 'There's probably less coding than before.'

Love and oblivion loom large - 'Laugh in the face of death on the masthead,' Adebimpe enjoins on 'Crying' - while the derisive portrait in 'Dancing Choose' of a 'newspaper man' who 'gets his ideas from the newspaper stand/ From his boots to his pen to his camera to his friends', seems to chime with Sitek's unflattering view of the media.

'I despise journalists,' he says. 'They try to tell me, without any credentials, what the world is thinking, what our communities are thinking... Lately I have almost entirely logged out. I'm putting more credence in the life I'm actually living than the life that's being described to me.'

A live wire of political feeling runs through most of TV on the Radio's work, though it is rarely grounded in direct, unambiguous expression. 'Dry Drunk Emperor', a free track released online in the aftermath of Hurricane Katrina, made an exception, dealing caustically with the Bush administration and its calamitous adventures in Iraq. Now that Bush is on the way out, with Barack Obama in the running to replace him, do the band have a brighter outlook on the future?

'Even if Obama does win, I'm under no illusion that a president is going to change an entire system that is erroneous at best,' says Sitek. 'If 45 Obamas got elected simultaneously and they all stuck to exactly what they said needed to be changed, then I'd be inclined to be a little more positive.'

Toss a topical issue into the TVOTR arena and it's bound to get torn in all directions. When talk turns to the future of the music industry, the four bandmates pounce on it with relish.

'The direction has always been to separate the artist from the audience,' says Sitek. 'When the music business collapses, it will go back to being a more communal experience.'

'It means that we'll have to learn how to grow food,' says Malone, 'or at least to play real good so that people will give us food.'

Before they resort to singing for their supper, the band - who signed to a major label in the US two years ago - have a few extracurricular cards up their sleeves. Adebimpe is in Rachel Getting Married, the upcoming Jonathan Demme picture. Malone is working on a solo project, Rain Machine, and has an album on the way. Sitek's production skills, which he has extended to bands such as Yeah Yeah Yeahs, Liars and Foals, are in such high demand that even Hollywood superstars have been seeking him out.

'Someone said "weird" and then my name came up,' he says, describing how Scarlett Johansson ended up asking him to produce her album of Tom Waits covers, Anywhere I Lay My Head. 'It was such a strange and out-there thing that I couldn't say no.' They spent five weeks together in the recording studio. 'Just her; no entourage. She was a lot more real than I imagine I would be in that situation.'

The most pressing issue right now is the new album's release and the ensuing tour. (TV on the Radio play in the UK next month.) When asked if they would consider themselves a hard-working band, the response is an unequivocal 'yes', and a muttered reference from Adebimpe to a 'trail of broken relationships'.

It must take its toll, trying to sustain the momentum of one of rock's most forward-thinking outfits. 'We don't smile any more,' confirms Adebimpe. 'We used to smile in the first year of this, but not now.' He leans forward conspiratorially. 'They use smiles to bury you.'

It takes a few seconds for the grin to emerge on his face. The last sounds I hear, as our lunch draws to a close and the time comes to leave TV on the Radio behind, are loud howls of laughter and, beneath that, the distant, dying strains of elevator music.

· Dear Science is released on September 22, and reviewed in Observer Music Monthly

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